An organic thin film transistor (OTFT) has advantages of simple manufacturing process, low cost and good flexibility and so on, and thus it is widely used in a panel display field. Therefore, researches and developments for the organic thin film transistor (OTFT) array substrate has been drawn attention widely. Several patterning processes are generally required during a process for manufacturing the OTFT array substrate to form a patterned layered structure. A typical OTFT has such a structure that gate electrodes and an active layer formed of organic semiconductor material are formed on a substrate with a gate insulating film interposed therebetween, source and drain electrodes spaced from each other contact the active layer and correspond to two sides of the gate electrode and are insulated from the gate electrodes. The organic semiconductor material generally has low chemical stability and optical stability, and thus it is very difficult and complicated to pattern the organic semiconductor material. An ink jet printing process is now developed to form an active layer of the OTFT. The ink jet printing process is a process of printing ink droplets (i.e. a solution formed by solving a material to be used to form a pattern into a certain solvent) in a region to be formed with a desired pattern so as to form the desired pattern.
During a process for manufacturing an OTFT or an OTFT array substrate, when an active layer of the OTFT is formed by the ink jet printing process, patterns of the active layer may not exactly meet process requirements, that is, the patterns of the active layer have not sufficient accuracy, due to fluidity of the ink droplets, so that the property of the OTFT may be influenced and thus the property of the OTFT array substrate may be influenced.